<!DOCTYPE html>
<html>
<head>
	<title>lineWidth</title>
</head>
<body>
	<canvas id="canvas" width="300" height="200px" style="border: 1px solid #ccc"></canvas>
	<script type="text/javascript">
		
		var c = document.getElementById("canvas");
		var ctx = c.getContext("2d");

		ctx.lineWidth = 15

		ctx.beginPath();
		ctx.moveTo(20,20)
		ctx.lineTo(130,130);

		ctx.rect(40,40,70,70)

		ctx.closePath();

		ctx.stroke()

		
	</script>
</body>
</html>